package org.bouncycastle.asn1.x509;

import java.io.IOException;

import org.bouncycastle.asn1.ASN1Encodable;
import org.bouncycastle.asn1.ASN1Object;
import org.bouncycastle.asn1.ASN1ObjectIdentifier;
import org.bouncycastle.asn1.ASN1OctetString;
import org.bouncycastle.asn1.DERBoolean;

/**
 * an object for the elements in the X.509 V3 extension block.
 */
public class X509Extension {
    /**
     * Subject Directory Attributes
     */
    public static final ASN1ObjectIdentifier subjectDirectoryAttributes = new ASN1ObjectIdentifier(
            "2.5.29.9");

    /**
     * Subject Key Identifier
     */
    public static final ASN1ObjectIdentifier subjectKeyIdentifier = new ASN1ObjectIdentifier(
            "2.5.29.14");

    /**
     * Key Usage
     */
    public static final ASN1ObjectIdentifier keyUsage = new ASN1ObjectIdentifier(
            "2.5.29.15");

    /**
     * Private Key Usage Period
     */
    public static final ASN1ObjectIdentifier privateKeyUsagePeriod = new ASN1ObjectIdentifier(
            "2.5.29.16");

    /**
     * Subject Alternative Name
     */
    public static final ASN1ObjectIdentifier subjectAlternativeName = new ASN1ObjectIdentifier(
            "2.5.29.17");

    /**
     * Issuer Alternative Name
     */
    public static final ASN1ObjectIdentifier issuerAlternativeName = new ASN1ObjectIdentifier(
            "2.5.29.18");

    /**
     * Basic Constraints
     */
    public static final ASN1ObjectIdentifier basicConstraints = new ASN1ObjectIdentifier(
            "2.5.29.19");

    /**
     * CRL Number
     */
    public static final ASN1ObjectIdentifier cRLNumber = new ASN1ObjectIdentifier(
            "2.5.29.20");

    /**
     * Reason code
     */
    public static final ASN1ObjectIdentifier reasonCode = new ASN1ObjectIdentifier(
            "2.5.29.21");

    /**
     * Hold Instruction Code
     */
    public static final ASN1ObjectIdentifier instructionCode = new ASN1ObjectIdentifier(
            "2.5.29.23");

    /**
     * Invalidity Date
     */
    public static final ASN1ObjectIdentifier invalidityDate = new ASN1ObjectIdentifier(
            "2.5.29.24");

    /**
     * Delta CRL indicator
     */
    public static final ASN1ObjectIdentifier deltaCRLIndicator = new ASN1ObjectIdentifier(
            "2.5.29.27");

    /**
     * Issuing Distribution Point
     */
    public static final ASN1ObjectIdentifier issuingDistributionPoint = new ASN1ObjectIdentifier(
            "2.5.29.28");

    /**
     * Certificate Issuer
     */
    public static final ASN1ObjectIdentifier certificateIssuer = new ASN1ObjectIdentifier(
            "2.5.29.29");

    /**
     * Name Constraints
     */
    public static final ASN1ObjectIdentifier nameConstraints = new ASN1ObjectIdentifier(
            "2.5.29.30");

    /**
     * CRL Distribution Points
     */
    public static final ASN1ObjectIdentifier cRLDistributionPoints = new ASN1ObjectIdentifier(
            "2.5.29.31");

    /**
     * Certificate Policies
     */
    public static final ASN1ObjectIdentifier certificatePolicies = new ASN1ObjectIdentifier(
            "2.5.29.32");

    /**
     * Policy Mappings
     */
    public static final ASN1ObjectIdentifier policyMappings = new ASN1ObjectIdentifier(
            "2.5.29.33");

    /**
     * Authority Key Identifier
     */
    public static final ASN1ObjectIdentifier authorityKeyIdentifier = new ASN1ObjectIdentifier(
            "2.5.29.35");

    /**
     * Policy Constraints
     */
    public static final ASN1ObjectIdentifier policyConstraints = new ASN1ObjectIdentifier(
            "2.5.29.36");

    /**
     * Extended Key Usage
     */
    public static final ASN1ObjectIdentifier extendedKeyUsage = new ASN1ObjectIdentifier(
            "2.5.29.37");

    /**
     * Freshest CRL
     */
    public static final ASN1ObjectIdentifier freshestCRL = new ASN1ObjectIdentifier(
            "2.5.29.46");

    /**
     * Inhibit Any Policy
     */
    public static final ASN1ObjectIdentifier inhibitAnyPolicy = new ASN1ObjectIdentifier(
            "2.5.29.54");

    /**
     * Authority Info Access
     */
    public static final ASN1ObjectIdentifier authorityInfoAccess = new ASN1ObjectIdentifier(
            "1.3.6.1.5.5.7.1.1");

    /**
     * Subject Info Access
     */
    public static final ASN1ObjectIdentifier subjectInfoAccess = new ASN1ObjectIdentifier(
            "1.3.6.1.5.5.7.1.11");

    /**
     * Logo Type
     */
    public static final ASN1ObjectIdentifier logoType = new ASN1ObjectIdentifier(
            "1.3.6.1.5.5.7.1.12");

    /**
     * BiometricInfo
     */
    public static final ASN1ObjectIdentifier biometricInfo = new ASN1ObjectIdentifier(
            "1.3.6.1.5.5.7.1.2");

    /**
     * QCStatements
     */
    public static final ASN1ObjectIdentifier qCStatements = new ASN1ObjectIdentifier(
            "1.3.6.1.5.5.7.1.3");

    /**
     * Audit identity extension in attribute certificates.
     */
    public static final ASN1ObjectIdentifier auditIdentity = new ASN1ObjectIdentifier(
            "1.3.6.1.5.5.7.1.4");

    /**
     * NoRevAvail extension in attribute certificates.
     */
    public static final ASN1ObjectIdentifier noRevAvail = new ASN1ObjectIdentifier(
            "2.5.29.56");

    /**
     * TargetInformation extension in attribute certificates.
     */
    public static final ASN1ObjectIdentifier targetInformation = new ASN1ObjectIdentifier(
            "2.5.29.55");

    boolean critical;
    ASN1OctetString value;

    public X509Extension(DERBoolean critical, ASN1OctetString value) {
        this.critical = critical.isTrue();
        this.value = value;
    }

    public X509Extension(boolean critical, ASN1OctetString value) {
        this.critical = critical;
        this.value = value;
    }

    public boolean isCritical() {
        return critical;
    }

    public ASN1OctetString getValue() {
        return value;
    }

    public ASN1Encodable getParsedValue() {
        return convertValueToObject(this);
    }

    public int hashCode() {
        if (this.isCritical()) {
            return this.getValue().hashCode();
        }

        return ~this.getValue().hashCode();
    }

    public boolean equals(Object o) {
        if (!(o instanceof X509Extension)) {
            return false;
        }

        X509Extension other = (X509Extension) o;

        return other.getValue().equals(this.getValue())
                && (other.isCritical() == this.isCritical());
    }

    /**
     * Convert the value of the passed in extension to an object
     * 
     * @param ext
     *            the extension to parse
     * @return the object the value string contains
     * @exception IllegalArgumentException
     *                if conversion is not possible
     */
    public static ASN1Object convertValueToObject(X509Extension ext)
            throws IllegalArgumentException {
        try {
            return ASN1Object.fromByteArray(ext.getValue().getOctets());
        } catch (IOException e) {
            throw new IllegalArgumentException("can't convert extension: " + e);
        }
    }
}
